The present invention relates to a printer including a frame composed of a lower frame and an upper frame supported on the lower frame, a platen rotatably supported in the upper frame for advancing a recording medium, a guide rail extending in parallel with an axial direction of the platen, a carriage guided at the guide rail and carrying a printhead, and a drive mechanism adapted to drive the carriage reciprocatingly along the guide rail.
A typical example of a printer of this type is an ink jet printer having a printhead or printheads adapted to expel droplets of liquid ink onto the recording medium that is advanced over the platen. The timings at which the nozzles of the printhead are energized must be accurately synchronized with the movement of the carriage relative to the recording medium. To this end, the carriage may be equipped with a detector for reading markings on a ruler. However, especially in a large format printer with a high throughput, the reciprocating carriage must be accelerated and decelerated rapidly, and this has the effect that the drive mechanism is subject to relatively high forces of inertia which must be absorbed by the frame structure. For this reason, the frame of a conventional printer has a very stiff construction so as to avoid distortions and vibrations which would degrade the print quality. This, however increases the costs and weight of the frame structure.